Will Lewis, now the publisher of the Washington Post, was in full crisis mode in 2011. Then an executive at a subsidiary of Rupert Murdoch’s News Corporation, he was an intermediary to the police detectives investigating a British phone-hacking scandal that had placed the company’s journalists and top leaders in legal peril.

For years, reporters at News Corporation’s best-selling British tabloid had landed scoops by paying public officials and illegally listening to the voice mail messages of royals, politicians, celebrities and even a murdered girl. Mr. Lewis was supposed to cooperate with the police, identify wrongdoing and help steer the company through the crisis.

His role, he would later say, was as a force for good. He was “draining the swamp.”

But confidential documents obtained by The New York Times and interviews with people involved in the criminal investigation show that, almost from the beginning, investigators with London’s Metropolitan Police were suspicious of the company’s intentions, and came to view Mr. Lewis as an impediment.

The police suspected that the company was trying to “steer the investigation into a very narrow remit” by pointing the finger at a few journalists “while steering the investigation away from other journalists and editors,” one of the lead detectives wrote in a previously undisclosed internal summary of events.

Scotland Yard detectives were shocked to learn that the company had deleted millions of internal emails, despite notices from a lawyer for an alleged phone hacking victim and the police explicitly asking that any documents related to the investigation be preserved, according to police records and interviews with investigators.

And while the company took steps to save some relevant emails amid the deletions, the police were deeply skeptical of one of Mr. Lewis’s explanations for those deletions — especially since he admitted it couldn’t be corroborated.

The Times reporting fills out a portrait of Mr. Lewis at a crucial moment. A British career journalist who became a crisis manager at the News Corp. subsidiary at the center of the phone-hacking scandal, he was thrust into a dual role as liaison to the authorities and, perhaps more important, as the protector of the Murdoch empire’s interests.

That job later propelled him into the heights of American media, as publisher first of The Wall Street Journal and now of The Post.

Today, he is again under pressure. His handpicked editor, Robert Winnett, abruptly withdrew from the job last week after news reports linked him and Mr. Lewis to British news-gathering practices that would be considered unethical in the United States.

High-profile lawsuits are also moving forward in London, brought against News Corp. by Prince Harry and other victims of hacking. The claims have not yet been tested in court but they include new details about Mr. Lewis’s role in the scandal. The episode has attracted even greater interest since Mr. Lewis tried to suppress news coverage of the litigation.

Journalists inside and outside The Post have questioned why he would do that if his role in the scandal had merely been to clean house.

The documents reviewed by The Times as well as those referenced in the lawsuits center on seven crucial months in the hacking scandal, from January to July 2011. Scotland Yard detectives met repeatedly with Mr. Lewis or his colleagues during that period, bargaining for access to evidence. Yet behind the scenes, the company was deleting data from its servers — and not telling the police until it was too late.

The company says this was all part of a planned computer system upgrade and was not an effort to hide evidence. And prosecutors, who reviewed evidence years ago, said they found no evidence to believe otherwise.

Mr. Lewis’s role is still not fully understood. But the lawsuits offer glimpses, citing reams of internal company documents. The plaintiffs say those records show that he was involved in the effort that deleted millions of internal emails, even as he presented himself as a conduit to the police.

Mr. Lewis, who is named in the lawsuits but is not personally being sued, declined an interview request. “Any allegations of wrongdoing are untrue,” he said in a statement. “I have no further comment to make.”

A spokeswoman for Mr. Murdoch’s British newspaper subsidiary disputed that there were tensions with the police. She said Mr. Lewis and other company representatives “acted throughout with the utmost integrity.”

The company also “strongly” denied allegations that it deleted emails to conceal evidence. Rather, she said, it was about upgrading a balky email system and creating needed additional storage capacity. As for the lawsuits, the spokeswoman said the company would respond thoroughly in court, but called the allegations “illogical, far-fetched and inherently incredible.”

Lawyers for both sides declined to comment or provide documents from the case beyond what was in the public file. Many of the court documents remain under seal.

One person now demanding a new investigation is Gordon Brown, a former prime minister of Britain, who had been the target of hacking and other surreptitious reporting methods.

When the police confronted Mr. Lewis about why certain emails had been removed from the servers, Mr. Lewis offered a startling response: He pointed the finger at Mr. Brown, according to police records reviewed by The Times.

The company removed the emails, Mr. Lewis told police, after receiving an unsubstantiated tip that Mr. Brown, a member of Parliament at the time, was plotting with his allies to steal emails of a top company executive.

Mr. Lewis conceded that he had no evidence to back up the tip, could never corroborate it and never mentioned it to the police until after the emails were deleted, according to police minutes of meetings.

Mr. Brown told The Times that the claims are “completely untrue and without any foundation at all.”

“I have been shocked to discover, as I did only recently, this false accusation against me,” he said. “The new allegations brought forward in court suggest that executives who claimed they were doing the cleanup may have instead been engaged in a cover-up.”

‘Will Lewis’ List’

In February 2011, investigators from Scotland Yard held meetings at the headquarters of the News of the World, the Murdoch tabloid at the heart of the hacking scandal.

The scandal had been gathering speed for five months. Lawyers for the actress Sienna Miller, who had long suspected that someone was hacking her phone, had put the company on notice to preserve any relevant material and then filed a lawsuit that contained explosive new evidence that would eventually lead to the suspension and firing of a top editor at the News of the World.

Under pressure, and in response to a police request for evidence, the company on Jan. 26 turned over three incriminating emails related to the editor.

That same day, Scotland Yard announced a new task force called Operation Weeting to investigate the extent of the hacking, who knew of it and who was responsible. The police told company executives to preserve all relevant documents going back a decade.

One of the officers that February day was Barney Ratcliffe, a detective inspector and homicide investigator. He met with company executives and lawyers for News International, a British subsidiary of News Corp., to hash out the terms of its cooperation.

They were not on the same page.

Mr. Ratcliffe wanted “as much information as possible.” Anything, he said, that “could establish or support the suggestion that employees at The News of the World had engaged in phone hacking,” according to his sworn statement, which contains a detailed summary of events and was filed in a separate court case.

The company said there wasn’t much information to give, meeting minutes show. The chief information officer, Paul Cheesbrough, told detectives that, for months, the company had been upgrading its corrupted and buggy email system. Because of that upgrade, he said, emails from before 2008 were gone.

The company had, however, preserved some emails that could be of interest in phone hacking litigation. Mr. Cheesbrough gave the police a list of criteria used to decide what to save. The company was willing to share what it had.

This largely limited the focus of the investigation to 18 people, police briefing notes show.

The plaintiffs in the lawsuit have dubbed this “Will Lewis’ List” because he had circulated it internally. Mr. Murdoch, his family and many top executives were not on it.

From one view, the list could be seen as an effort to preserve evidence for the police by sequestering the emails of potential suspects as News International upgraded its system, which is what News UK, as the company is now known, described in a statement given to The Times.

The plaintiffs have a different perspective. They say it was a plan to “cover up and conceal” evidence of wrongdoing by saving only some emails — and getting rid of everything else.

In either case, millions of emails were wiped off the server.

All Mr. Ratcliffe, the detective inspector, knew was that he disliked the company’s proposal from the beginning. It seemed designed to point the finger at a handful of journalists whom it was willing to “hang out to dry,” he said in his court statement, while steering Scotland Yard, which is formally known as the Metropolitan Police Service, away from others.

“I took the view that it should be for the M.P.S., as the investigators, to decide what should be investigated rather than the organization which had caused or permitted phone hacking to take place,” Mr. Ratcliffe said in his sworn statement.

Investigators were so frustrated, the records show, that at one point they considered using their search-and-seizure powers. But declaring newspaper offices a crime scene and scouring them for evidence would trample on journalistic independence and surely mire the investigation in court fights.

Winning the company’s voluntary cooperation seemed more expedient.

‘Green Light’

As Mr. Cheesbrough described a long-planned email upgrade in that Feb. 9 meeting, police minutes indicate and detectives say that he left out a fact that investigators have only learned recently, as evidence has emerged in the hacking lawsuit: The bulk of the emails had been deleted only days earlier, in the investigation’s key early days. And Mr. Lewis was involved in that decision.

In January, the company deleted about 11 million emails, according to the lawsuits.

Then, on Feb. 3, Mr. Lewis sent an email giving a “green light” to delete another 15.2 million emails, according to claims by the plaintiffs, citing News Corporation records.

It was only in March, after these deletions, that the company and the police reached an agreement. Going forward, detectives could ask the company to do key word and name searches, which would be handled by a third party, then filtered through the company to consider raising objections.

By April, the company had handed over just 54 emails, according to the plaintiffs’ filings.

It was around this time that Mr. Lewis became the primary point of contact for the police, helping solidify his reputation as a crucial cooperator. The Guardian newspaper, which broke open the phone hacking scandal, called him “News Corp’s cleanup campaigner.” Even Sue Akers, the head of the task force, would later say that the relationship with the company improved when Mr. Lewis arrived.

But the detectives closest to the case quickly came to doubt this new spirit of cooperation. As potential evidence began to be turned over under the new protocol, Detective Sgt. Wayne Harknett, a computer specialist, noticed something odd. Even given the deletions, “Emails which we had expected to find did not appear to be present,” he said in a previously unreported document.

And in a pair of interviews in the spring, investigators got a glimpse at just how many emails had been deleted — and from whose accounts.

First, a private computer consultant said that he’d been told by News International to remove emails, including from top executives, from the company server, according to a statement he gave the police. He said he warned the company that they might never be recoverable, and he was told to do it anyway.

Then, another outside tech consultant told the police that he had deleted the metadata — the sender, recipient, time and date — for millions of News International emails, according to Mr. Ratcliffe’s sworn statement.

That did not sound to the police like the routine computer modernization the company had described.

Both consultants separately told detectives that the deletions had occurred back in January, records show. The police were stunned. That meant that, during the crucial early period of the investigation, after Scotland Yard had first asked the company for evidence, News International was deleting data from its servers without mentioning it.

On June 23, the police caught a break, records show. In a meeting with Mr. Cheesbrough, yet another outside IT consultant weighed in — and dropped a bombshell.

He volunteered that, before the deletions began, he had backed up the company’s entire email system. Even emails predating 2008 should be recoverable.

“Mr. Cheesbrough appeared to be totally shocked by this development: it felt as though the cat had been let out of the bag,” Mr. Ratcliffe wrote of the encounter. “It was a jaw-dropping moment for most of the attendees at the meeting.”

A company spokeswoman, speaking on behalf of Mr. Cheesbrough, acknowledged that it was “new news” to the company but disputed Mr. Cheesbrough’s expression.

Mr. Ratcliffe’s skepticism of News International deepened. He was particularly incensed to learn about the backups from an outside consultant, and not the company, according to his sworn statement.

“Whether NI itself knew of this backup and sought to hide it, or were simply unaware of what existed, either way, it was an unacceptable state of affairs,” Mr. Ratcliffe said.

Mr. Lewis’s Explanation

On July 8, as technicians prepared to restore the lost emails using the newly discovered backup, the police held a tense meeting with Mr. Lewis and Mr. Cheesbrough.

The detectives confronted them about what the first IT consultant had said. Did the company really ask him to remove the emails of key executives from the servers?

Mr. Cheesbrough responded that some of the emails had been extracted and “purged” after the company learned of a security threat involving the former prime minister, Mr. Brown, minutes show.

“This has had an impact on our investigation,” Mr. Ratcliffe said, according to the minutes.

Had the company documented the threat?

Mr. Cheesbrough said it had not.

Mr. Lewis added that one of the company’s top executives, Rebekah Brooks, had been the target. And he told them that Mr. Brown’s ally Tom Watson, a member of Parliament who was an early critic of News Corporation over phone hacking, had been the intermediary.

“We got a warning from a source that a current member of staff had got access to Rebekah’s emails,” he said. He met with the source, he added, who said that “emails had definitely been passed and that it was controlled by Gordon Brown.”

“We apologize for hiding this piece of work from you,” Mr. Lewis said.

When the investigators kept pressing, eventually Mr. Lewis acknowledged that the story was unsubstantiated: “We have our suspicions,” he said, “but we don’t have any evidence.”

Two investigators involved in Operation Weeting told The Times that Mr. Lewis never followed up. Both found the story not credible. It “doesn’t make any sense,” said one. “Complete nonsense,” another said.

Ms. Akers, who headed the police investigation, only learned of this explanation recently and said she found it unbelievable. “Gordon Brown was obviously one of the victims,” she said. “The thought that he would do that is ludicrous.”

A News Corporation spokeswoman said the security threat was not used to justify deleting information.

For his part, Mr. Watson, the member of Parliament accused by Mr. Lewis, said the allegation is “utterly absurd” and “was deliberately concocted by News International in an attempt to justify the destruction and concealment of millions of relevant emails during a criminal investigation.”

Insufficient Evidence

The News of the World was forced to close in July 2011, but otherwise News Corporation weathered the phone hacking scandal, as did the media executives at the top of the company.

Ms. Brooks was charged on five criminal counts, including conspiracies to hack phones and to pervert the course of justice, but was acquitted in 2014. She returned to News Corporation the following year and now serves as chief executive of the subsidiary that oversees Mr. Murdoch’s Sunday Times, The Times of London and his remaining popular tabloid, The Sun.

In November 2015, Scotland Yard shut down Operation Weeting. All told, some 30 million emails were deleted or lost from News International company servers. Using the consultant’s backup, tech specialists, with the company’s required help, recovered around two-thirds — but 10 million were gone.

Ms. Akers, who headed the Weeting investigation and had once praised Mr. Lewis for his cooperation, says information that has emerged in the lawsuits has shifted her view. In an interview with The Times, she said she never would have said those things if she had believed then that Mr. Lewis was involved “in the destruction” of what she would have considered potentially relevant evidence.

Before shuttering the operation, the police passed what they had learned to the Crown Prosecution Service to decide whether to charge the company with a crime.

The prosecutors ultimately announced that they had considered bringing charges against News International in relation to, among other things, its email deletion policy. Prosecutors concluded that “there is no evidence to suggest the email deletion was undertaken in order to pervert the course of justice.”

Despite numerous lawsuits over phone hacking, none has gone to trial. The company has always settled, so there has never been a public accounting in court. The company said it will file its response to claims in the latest cases next month.

Mr. Cheesbrough, Mr. Lewis’s colleague who handled IT matters including the deletions, got two big promotions within the company. In 2012 he became the chief technology officer for News Corp. and later the chief executive of a Fox Corp. subsidiary.

For his part, Mr. Lewis was promoted to chief executive of Dow Jones, the News Corp. subsidiary that publishes The Wall Street Journal, the jewel of the Murdoch newspaper empire, before taking the helm as publisher of The Washington Post.

“I did my bit to help with the legal process,” Mr. Lewis told the Evening Standard in 2017 of his time dealing with the phone hacking scandal. “One day,” he added, “the truth will be written.”